For several decades, external systems separate from a golf club, or attaching sensors to a golf club, have been used to gather and infer information about the effectiveness of a golfer's swing. One of the most common external systems relates to using high speed cameras to determine metrics about a golfer's swing. Some of these systems estimate club head speed and ball speed and spin after the ball leaves the club. However, the true forces introduced in the clubface and the club/ball impact information are estimates based upon indirect calculations of force inferred from optical images.
The approach of using prior art golf club attachments can identify to an unacceptable approximate degree the impact area on the clubface. However, the precise location cannot be achieved because of the removable nature of the sensors and the lack of relationship of time varying force profiles of each sensor which is needed for a full energy impact analysis.
An example of such an external system is U.S. Pat. No. 4,136,387 to Sullivan et al., for a Golf Club Impact And Golf Ball Launching Monitoring System. Sullivan discloses a system that uses external electro-optical sensors to measure the location of a plurality of spots on the surface of the golf club head or the golf ball, each at two points in time. For the golf club head measurement the two points in time are just before ball impact; for the two points in time for the golf ball, it is after impact. This device does not offer an integrated golf club and does not allow for direct force measurements of the time varying spatial and force profiles across the clubface and club head accelerations' forces for accurate force dynamics associated with the club swing and clubface/ball impact.
Another example of an external system is the Patent Application Publication U.S. 2008/0020867 A1 to Manwaring for a method of determining a golfer's golf club head orientation and impact location for a golf swing. The system uses an optical CMOS imaging system to measure angular velocity of the golf club, linear velocity of the golf club, and ball launch properties. Then, through iterative calculations using the mass of the golf club and the ball, the device makes determinations as to club head orientation and clubface impact. This publication does not offer an integrated golf club and does not allow for direct force measurements of the time varying spatial and force profiles across the clubface and club head accelerations' forces for accurate force dynamics associated with the club swing and clubface/ball impact.
Another example of an external system is shown in U.S. Pat. No. 7,329,193 B2 to Plank, Jr. who claims a portable golf swing analyzing system separate from the golf club based on infrared sensors and ultrasonic sensors. This publication does not offer an integrated golf club and does not allow for direct force measurements of the time varying spatial and force profiles across the clubface and club head accelerations' forces for accurate force dynamics associated with the club swing and clubface/ball impact.
An example of attaching sensors to a golf club is shown in U.S. Pat. No. 4,898,389 to Plutt, who claims a self contained device for indicating the area of impact on the face of the club and the ball, and a means for an attachable and detachable sensor or sensor array that overlies the face of the club. Plutt's device does not provide for an imbedded impact sensor array in the clubface that functions in conjunction with internal three dimensional g-force sensors to provide a superset of time varying spatial force impact contours of the clubface with club head acceleration force parameters that can be calibrated for highly accurate spatial and force measurement. Plutt's device is susceptible to location inaccuracy due to the removable constraint of the sensors and is susceptible to sensor damage since the sensors come in direct contact with the ball.
Another example of attaching sensors to a golf club is shown in U.S. Pat. No. 7,264,555 B2 to Lee et al. which claims a diagnostic golf club system that utilizes a golf club with strain gauges or other swing load measuring means attached to the golf club shaft to determine swing characteristics. This device does not utilize sensors embedded with in the club head.
Another example of attaching sensors to a golf club is U.S. Pat. No. 5,792,000 to Weber et al. which claims a swing analysis system that analyzes sensors placed on the shaft of the golf club. This device does not utilize sensors embedded within the club head.
The prior art disclosures all fail to offer a fully integrated golf club capable of autonomously making time varying direct force measurements with regards to three dimensional motional forces of the club head before, during and after golf club head/ball impact, and making direct time varying force measurements across the clubface surface. Accordingly, none of the prior art aggregates all of these direct measurements with respect to a single time line allowing a large number of metrics to be calculated.